Year Percent 1960-01-01 40.26780000000000 1961-01-01 38.53580000000000 1962-01-01 38.73830000000000 1963-01-01 40.22700000000000 1964-01-01 40.34440000000000 1965-01-01 40.57360000000000 1966-01-01 41.47080000000000 1967-01-01 42.15410000000000 1968-01-01 44.50700000000000 1969-01-01 44.63320000000000 1970-01-01 41.62080000000000 1971-01-01 40.80110000000000 1972-01-01 40.72920000000000 1973-01-01 40.79360000000000 1974-01-01 40.28390000000000 1975-01-01 37.97730000000000 1976-01-01 38.10230000000000 1977-01-01 39.78120000000000 1978-01-01 40.01380000000000 1979-01-01 39.85240000000000 1980-01-01 38.53100000000000 1981-01-01 39.09760000000000 1982-01-01 39.60920000000000 1983-01-01 38.45290000000000 1984-01-01 37.06150000000000 1985-01-01 37.10350000000000 1986-01-01 37.60520000000000 1987-01-01 39.98610000000000 1988-01-01 44.54520000000000 1989-01-01 49.98290000000000 1990-01-01 53.71660000000000 1991-01-01 52.64500000000000 1992-01-01 51.24410000000000 1993-01-01 44.09830000000000 1994-01-01 35.62020000000000 1995-01-01 32.10900000000000 1996-01-01 31.63980000000000 1997-01-01 33.07080000000000 1998-01-01 34.84820000000000 1999-01-01 36.22010000000000 2000-01-01 37.89020000000000 2001-01-01 65.63990000000000 2002-01-01 92.01000000000000 2003-01-01 93.08170000000000 2004-01-01 93.39790000000000 2005-01-01 97.65770000000000 2006-01-01 101.77700000000000 2007-01-01 107.54600000000000 2008-01-01 117.51000000000000 2009-01-01 124.79200000000000 2010-01-01 120.28900000000000 2011-01-01 123.12100000000001 2012-01-01 127.58500000000000 2013-01-01 129.39300000000000 2014-01-01 128.48400000000000 2015-01-01 125.40299999999999 2016-01-01 125.42500000000000